The Doctor, Tegan and Turlough find themselves in 1215 England. They
arrive at the castle of Ranulf Fitzwilliam, and are astounded to find
King John there too, especially since he is supposed to be in London at
the same time, involved in the events which will lead to the signing of
the Magna Carta. The time travellers discover that the King is not who
he claims -- in fact, he is a shapechanging robot named Kamelion under
the influence of the Master, who is trying to irreversibly pervert the
course of Earth's history.

Production

By late 1981, freelance effects designer Richard Gregory had been
involved in several Doctor Who serials through his company,
Imagineering. In November, Gregory approached producer John
Nathan-Turner about a project developed by CP Cybernetics, a computer
company owned by Chris Padmore, in conjunction with software designer
Mike Power. Padmore and Power had devised a functioning robot prop,
whose body could move and which could mime speech along to prerecorded
dialogue. Work on perfecting a system which would enable the android to
walk was also under way. Unfortunately, Padmore had run out of money,
and efforts to secure additional funding -- both from the commercial
sector and through a possible involvement in the movie Xtro --
had come to naught. Padmore had then contacted Gregory, who thought that
the robot might find a use on Doctor Who.

Nathan-Turner was intrigued by Gregory's pitch, and consented to meet
with Padmore. In late November, he and script editor Eric Saward were
given a demonstration of the prototype by Gregory and Padmore.
Nathan-Turner and Saward were impressed, sensing that the android might
appeal to the public in the same way as K·9 four years earlier. They
agreed that the waters should be tested in a short adventure; if this
proved successful, the robot might become a regular companion for the
Doctor.

John Nathan-Turner sensed that the android might appeal to
the public in the same way as K·9

To write the android's initial story, Nathan-Turner favoured television
veteran Terence Dudley. Saward was less content with this decision. In
the last year, Dudley had scripted Four To
Doomsday and Black Orchid for
Doctor Who, plus A Girl's Best
Friend, the pilot episode for the unsuccessful spin-off K·9
And Company. Saward was not impressed with Dudley's work, and the
two did not get along. Nonetheless, Nathan-Turner forged ahead, and a
second demonstration of the robot was arranged for Dudley's benefit
around Christmastime. At this point, Nathan-Turner formally agreed to
use the robot, although he requested that Padmore continue to improve
upon it. In particular, the producer wanted the android to be more
mobile, and hoped that the prop could be made to walk by the time its
debut story went before the cameras.

In addition to the robot's introduction, Dudley was told that his
storyline should incorporate the return of the Master. Anthony Ainley
had been contracted to appear in one serial during Season Twenty
(although Nathan-Turner had originally envisioned the Master appearing
in two stories per year), but no suitable adventure had yet presented
itself. Now Nathan-Turner felt that pairing the Master with the android
would be an interesting new way to use the villain. Again, Saward
disagreed with his producer: he felt that the Master was an inferior
character, and was not eager to bring him back every year.

With these requirements in mind, Dudley resurrected an idea he had been
contemplating prior to writing Black
Orchid, which would take the TARDIS to the thirteen-century
England of King John. Into this, Dudley brought the Master -- operating
under the alias of Sir Gilles Estram, “Estram” being an
anagram of “Master”. Keeping in mind the robot's
limitations, Dudley decided to make it a shapeshifter, so that an actor
could play the role as necessary; it was also Dudley who coined the name
Kamelion. On February 22nd, 1982, Dudley was commissioned to write
“The Android”. His scripts apparently went through several
other working titles -- including “The Demons”, “A
Knight's Tale” and, according to some publicity photos,
“Demons Keeper” -- before becoming known as The King's
Demons.

The King's Demons was intended to be the penultimate story of
Season Twenty, both in terms of production and broadcast, and was
designated Serial 6J. The young director assigned to the story was Tony
Virgo, who had been a production assistant on shows such as Blake's
7, and who had recently helmed episodes of Angels. The
King's Demons would be Virgo's only Doctor Who story; he
subsequently directed episodes of programmes including All Creatures
Great And Small and EastEnders before becoming a producer,
working on Dalziel And Pascoe and Peak Practice, amongst
others.

One of Virgo's responsibilities was to “cast” the potential
new companion. To provide the voice of Kamelion, he approached veteran
actor Gerald Flood, who had appeared in the feature film Patton,
and whose television work included Crane and The Rat
Catchers. Flood had also starred in the early Sixties
science-fiction series Pathfinders In Space and its sequels,
which had been produced by Doctor Who creator Sydney Newman. In
addition to his vocal duties in The King's Demons, Flood would
also play the role of King John. Meanwhile, it was decided that the
Master's appearance in the story would be masked by crediting Anthony
Ainley under a pseudonym, “James Stoker”, which was an
anagram of “Master's joke”.

As work began on The King's Demons, a pall hung over Doctor
Who, and indeed the BBC as a whole. The electricians' union had been
threatening strike action for weeks, and the picket lines finally went
up in early November. As a result, Enlightenment -- the story which immediately
preceded The King's Demons -- was suspended in mid-production,
its location filming having been completed but its studio dates
indefinitely postponed. Concern now arose that both The King's
Demons and “The Return”, the Dalek story intended to
close the season, would have to be abandoned. Nonetheless, Nathan-Turner
elected to proceed with location work on The King's Demons, in
the hope that the industrial dispute would be settled by the time Serial
6J was scheduled to move into the studio.

Dudley's script described The King's Demons as being set at
Odiham Castle, near Basingstoke in Hampshire. This was based on
historical fact: it was from either Odiham or Windsor Castle that King
John departed for Runnymede, where the Magna Carta was signed. However,
Odiham Castle had fallen into ruins by the start of the seventeenth
century, with only a section of the octagonal keep now standing.
Instead, Virgo took his team to Bodiam Castle, at Bodiam in East Sussex,
which was the nearest castle to London in serviceable condition. Work
inside and on the grounds of Bodiam Castle took place from December 5th
to 7th.

Around this time, the labour dispute between the BBC and its
electricians was resolved. This meant that The King's Demons
could be completed on schedule. However, it was too late to fully
salvage the season: Enlightenment would
have to be finished during the studio dates originally meant for
“The Return”, while the Dalek story would be postponed and
made as part of Season Twenty-One. Consequently, The King's
Demons would now be the season finale. Originally, Serial 6J ended
with a cliffhanger leading into “The Return”, as the TARDIS
becomes trapped in a time corridor. Tegan asks if this is the Master's
doing, but the Doctor suspects an even more malign force at work. Saward
replaced this scene with one which foreshadowed the Doctor's trip to
the idyllic Eye of Orion -- a reference to the opening scenes of The Five Doctors, a twentieth-anniversary
special being prepared for transmission in November 1983.

Mike Power had been killed in a boating accident, and no
one else understood Kamelion's software

Meanwhile, the production team was having second thoughts about the
viability of the Kamelion prop. Mike Power had been killed in a boating
accident, and no one else possessed the necessary understanding of the
software which drove the robot. As a result, Padmore had been unable to
perfect the walking mechanism, and it took weeks to program all of
Kamelion's dialogue. It became clear that Kamelion could not be retained
as a regular member of the TARDIS crew, and Nathan-Turner decided that
he would be brought back for just one more story, to air sometime during
Season Twenty-One, in which he would be written out of Doctor
Who.

The single studio block allocated to The King's Demons took place
on December 19th and 20th, in BBC Television Centre Studio 1. The sets
for the Great Hall and the dungeon were used on both days, with scenes
in the guest chamber taped on the 19th, and material in the King's
chamber and both TARDISes on the 20th. Unfortunately, the problems with
Kamelion proved even more severe than anticipated. The prop constantly
broke down, and proved unable to maintain synchronisation with Flood's
prerecorded dialogue. Virgo completed as much footage as he could, but
several Kamelion scenes, as well as a number of sequences in the TARDIS,
could not be finished by the end of the day.

Fortunately, Nathan-Turner was able to schedule an extra studio day in
TC1 on January 16th, immediately before Enlightenment belatedly began its first
recording session. The outstanding scenes in the King's chamber and the
TARDIS were completed, bringing the troubled production to an end. Two
months later, the second installment of The King's Demons marked
the premature conclusion of Season Twenty. It had been an uneven year,
with audience figures down sharply on Season Nineteen. Indeed, at times
the number of viewers had dropped to about the same levels measured
during Season Eighteen, which had been part of the impetus for
relocating Doctor Who to weekday nights.

The King's Demons was Terence Dudley's last televised
contribution to Doctor Who, although he would subsequently
novelise Black Orchid, The King's
Demons and A Girl's Best Friend
for Target Books. He continued to work occasionally as a director, such
as on the All Creatures Great And Small Christmas special in
1983. Dudley passed away on December 25th, 1988, after a long bout with
cancer.